diff --git a/packages/react-native-executorch-webrtc/android/build.gradle b/packages/react-native-executorch-webrtc/android/build.gradle
index 919f9d2666..da727c1f6d 100644
--- a/packages/react-native-executorch-webrtc/android/build.gradle
+++ b/packages/react-native-executorch-webrtc/android/build.gradle
@@ -13,7 +13,13 @@ buildscript {
 }
 
 apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android'
+// AGP 9 ships built-in Kotlin support and registers the `kotlin` extension
+// itself. Applying the Kotlin plugin on top of it fails configuration with
+// "Cannot add extension with name 'kotlin'". Only apply it when nothing has
+// registered that extension yet.
+if (project.extensions.findByName('kotlin') == null) {
+    apply plugin: 'kotlin-android'
+}
 
 android {
     namespace 'com.executorch.webrtc'
@@ -51,9 +57,11 @@ android {
         targetCompatibility JavaVersion.VERSION_17
     }
 
-    kotlinOptions {
-        jvmTarget = '17'
-    }
+    // No `kotlinOptions` block: it comes from the Kotlin plugin, which is not
+    // applied on AGP 9, so referencing it there fails with "Could not find
+    // method kotlinOptions()". Both AGP 8 and AGP 9 take the Kotlin jvmTarget
+    // from `compileOptions` above; verified to emit Java 17 bytecode on
+    // AGP 8.13.2 and AGP 9.4.0.
 
     packaging {
         jniLibs {
diff --git a/packages/react-native-executorch/android/build.gradle.kts b/packages/react-native-executorch/android/build.gradle.kts
index 4b8ff5ca66..01d75e11be 100644
--- a/packages/react-native-executorch/android/build.gradle.kts
+++ b/packages/react-native-executorch/android/build.gradle.kts
@@ -2,10 +2,18 @@ import groovy.json.JsonSlurper
 
 plugins {
     id("com.android.library")
-    id("org.jetbrains.kotlin.android")
+    // Kept on the classpath but not applied here: AGP 9 ships built-in Kotlin
+    // support and registers the `kotlin` extension itself, so applying the
+    // Kotlin plugin on top fails with "Cannot add extension with name
+    // 'kotlin'". Applied conditionally below instead.
+    id("org.jetbrains.kotlin.android") apply false
     id("com.facebook.react")
 }
 
+if (project.extensions.findByName("kotlin") == null) {
+    apply(plugin = "org.jetbrains.kotlin.android")
+}
+
 /**
  * Helper function to get variables from the root project (App level)
  * or fall back to local project properties.
@@ -116,9 +124,11 @@ android {
         targetCompatibility = JavaVersion.VERSION_17
     }
 
-    kotlinOptions {
-        jvmTarget = "17"
-    }
+    // No `kotlinOptions` block: its type-safe accessor is generated only when
+    // the Kotlin plugin is applied from the `plugins` block, which it no longer
+    // always is. Both AGP 8 and AGP 9 take the Kotlin jvmTarget from
+    // `compileOptions` above; verified to emit Java 17 bytecode on AGP 8.13.2
+    // and AGP 9.4.0.
 }
 
 repositories {